Num() formats a parameter value according to a format specification (OUTPUT) e.g. LET vOutput = Num(12345, '$ #.00') will store something like '$ 12345.00' into vOutput
Num#() forces interpretation of a parameter value according to a fixed pattern (INPUT) e.g. a column in a LOAD statement like <Num#(InputValue, '0.00', ',', '.') as NewColumn> will lift the digits, force interpretation with the sepcificed separators as a number and store the resulting value in NewColumn.
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